From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44297C0650E for ; Wed, 3 Jul 2019 20:35:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1E5E6218A3 for ; Wed, 3 Jul 2019 20:35:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727384AbfGCUfB (ORCPT ); Wed, 3 Jul 2019 16:35:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43944 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727340AbfGCUfA (ORCPT ); Wed, 3 Jul 2019 16:35:00 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 434955944C; Wed, 3 Jul 2019 20:34:55 +0000 (UTC) Received: from x1.home (ovpn-116-83.phx2.redhat.com [10.3.116.83]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3E4FC18248; Wed, 3 Jul 2019 20:34:52 +0000 (UTC) Date: Wed, 3 Jul 2019 14:34:51 -0600 From: Alex Williamson To: Shameer Kolothum Cc: , , , , , , , , Subject: Re: [PATCH v7 3/6] vfio/type1: Update iova list on detach Message-ID: <20190703143451.0ae4e9f7@x1.home> In-Reply-To: <20190626151248.11776-4-shameerali.kolothum.thodi@huawei.com> References: <20190626151248.11776-1-shameerali.kolothum.thodi@huawei.com> <20190626151248.11776-4-shameerali.kolothum.thodi@huawei.com> Organization: Red Hat MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Wed, 03 Jul 2019 20:35:00 +0000 (UTC) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Wed, 26 Jun 2019 16:12:45 +0100 Shameer Kolothum wrote: > Get a copy of iova list on _group_detach and try to update the list. > On success replace the current one with the copy. Leave the list as > it is if update fails. > > Signed-off-by: Shameer Kolothum > --- > drivers/vfio/vfio_iommu_type1.c | 91 +++++++++++++++++++++++++++++++++ > 1 file changed, 91 insertions(+) > > diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c > index b6bfdfa16c33..e872fb3a0f39 100644 > --- a/drivers/vfio/vfio_iommu_type1.c > +++ b/drivers/vfio/vfio_iommu_type1.c > @@ -1873,12 +1873,88 @@ static void vfio_sanity_check_pfn_list(struct vfio_iommu *iommu) > WARN_ON(iommu->notifier.head); > } > > +/* > + * Called when a domain is removed in detach. It is possible that > + * the removed domain decided the iova aperture window. Modify the > + * iova aperture with the smallest window among existing domains. > + */ > +static void vfio_iommu_aper_expand(struct vfio_iommu *iommu, > + struct list_head *iova_copy) > +{ > + struct vfio_domain *domain; > + struct iommu_domain_geometry geo; > + struct vfio_iova *node; > + dma_addr_t start = 0; > + dma_addr_t end = (dma_addr_t)~0; > + > + list_for_each_entry(domain, &iommu->domain_list, next) { > + iommu_domain_get_attr(domain->domain, DOMAIN_ATTR_GEOMETRY, > + &geo); > + if (geo.aperture_start > start) > + start = geo.aperture_start; > + if (geo.aperture_end < end) > + end = geo.aperture_end; > + } > + > + /* Modify aperture limits. The new aper is either same or bigger */ > + node = list_first_entry(iova_copy, struct vfio_iova, list); > + node->start = start; > + node = list_last_entry(iova_copy, struct vfio_iova, list); > + node->end = end; > +} > + > +/* > + * Called when a group is detached. The reserved regions for that > + * group can be part of valid iova now. But since reserved regions > + * may be duplicated among groups, populate the iova valid regions > + * list again. > + */ > +static int vfio_iommu_resv_refresh(struct vfio_iommu *iommu, > + struct list_head *iova_copy) > +{ > + struct vfio_domain *d; > + struct vfio_group *g; > + struct vfio_iova *node; > + dma_addr_t start, end; > + LIST_HEAD(resv_regions); > + int ret; > + > + list_for_each_entry(d, &iommu->domain_list, next) { > + list_for_each_entry(g, &d->group_list, next) > + iommu_get_group_resv_regions(g->iommu_group, > + &resv_regions); Need to account for failure case here too. > + } > + > + if (list_empty(&resv_regions)) > + return 0; > + > + node = list_first_entry(iova_copy, struct vfio_iova, list); > + start = node->start; > + node = list_last_entry(iova_copy, struct vfio_iova, list); > + end = node->end; > + > + /* purge the iova list and create new one */ > + vfio_iommu_iova_free(iova_copy); > + > + ret = vfio_iommu_aper_resize(iova_copy, start, end); > + if (ret) > + goto done; > + > + /* Exclude current reserved regions from iova ranges */ > + ret = vfio_iommu_resv_exclude(iova_copy, &resv_regions); > +done: > + vfio_iommu_resv_free(&resv_regions); > + return ret; > +} > + > static void vfio_iommu_type1_detach_group(void *iommu_data, > struct iommu_group *iommu_group) > { > struct vfio_iommu *iommu = iommu_data; > struct vfio_domain *domain; > struct vfio_group *group; > + bool iova_copy_fail; > + LIST_HEAD(iova_copy); > > mutex_lock(&iommu->lock); > > @@ -1901,6 +1977,12 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, > } > } > > + /* > + * Get a copy of iova list. If success, use copy to update the > + * list and to replace the current one. > + */ > + iova_copy_fail = !!vfio_iommu_iova_get_copy(iommu, &iova_copy); > + > list_for_each_entry(domain, &iommu->domain_list, next) { > group = find_iommu_group(domain, iommu_group); > if (!group) > @@ -1926,10 +2008,19 @@ static void vfio_iommu_type1_detach_group(void *iommu_data, > iommu_domain_free(domain->domain); > list_del(&domain->next); > kfree(domain); > + if (!iova_copy_fail && !list_empty(&iommu->domain_list)) > + vfio_iommu_aper_expand(iommu, &iova_copy); > } > break; > } > > + if (!iova_copy_fail && !list_empty(&iommu->domain_list)) { > + if (!vfio_iommu_resv_refresh(iommu, &iova_copy)) > + vfio_iommu_iova_insert_copy(iommu, &iova_copy); > + else > + vfio_iommu_iova_free(&iova_copy); > + } The iova_copy_fail and list_empty tests are rather ugly, could we avoid them by pushing the tests to the expand and refresh functions? ie. it looks like vfio_iommu_aper_expand() could test list_empty(iova_copy), the list_for_each on domain_list doesn't need special handling. Same for vfio_iommu_resv_refresh(). This would also fix the bug above that I think we don't free iova_copy if domain_list becomes empty during this operation. Thanks, Alex